Power transmission and control means therefor



March 23, 1943. e. R. PENNINGTON 2,314,554

POWER TRANSMISSION AND CONTROL MEANS THEREFOR Filed Sept. 17, 1938 7 Sheets-Sheet 1 11v VENTOR gar-67 22 7f F I2HZ'ngZ IZ L262 BY (75.9 ATTORNEYS- March 23, 1943. e. R. PENNINGTON 2,314,554

POWER TRANSMISSION AND CONTROL MEANS THEREFOR Filed Sept. 1'7, 1938 u 7 Sheets-Sheet 2 i m VENTOR B Y garda/Z 7f 7lrzzz'rz giazz,

G. R. PENNINGTON March 23, 1943. I

4 POWER TRANSMISSION AND CONTROL MEANS THEREFOR Filed Sept. 17, 1938 7 Sheets-Sheet 3 4 K INVENTOR 0 65 217: 2?. 2 27 72 5017, BY. I 6 5 g I A TTORNEY March 23, 1943. PENNINGTON 2,314,554

POWER TRANSMISSION AND CONTROL MEANS THEREFOR Filed Sept. 17, 1938 '7 Sheets-Sheet 4 oraazz Z 77701 275202?! March 1943- G. R. PENNINGTON ,3

POWER TRANSMISSION AND CONTROL MEANS THEREFOR Filed Sept. 17, 1938 7 Sheets-Sheet 5 @ia E March 23, 1943.

a. R. PENNINGTON POWER TRANSMISSION AND CONTROL MEANS THEREFOR Filed Sept. 17, 1938 '7 Sheets-Sheet 6 [N VENTOR ar/a 7?. 7?. 17272275Z Z BY Z A TTORNE Y3 March 23, 1943. I PENNlNGTON 2,314,554

POWER TRANSMISSION AND CONTROL MEANS THEREFOR Filed Sept. 17, 1938 '7 Sheets-Sheet '7 \I 300 a )N f ku r MI g 1 a W PATTORNEYS.

Patented Mar. 23, 1943 POWER TRANSDIISSION AND GONTROL MEANS THEREFOR Gordon R. Pennington, Birmingham, Mich., as-

signor to Chrysler Corporation, Highland Park, Mich., a corporation of Delaware Application September 17, 1938, Serial No..230,417

29 Claims.

. other drives.

Another object is to provide an improved pressure fluid governing system operating automatically in response to predetermined desired conditions of pressure fluid delivery for effecting control of any suitable motor vehicle fluid operated device.

My pressure-fluid control system may be used in conjunction with power transmissions, for

example, for effecting change in the speed ratio drive of the vehicle. An application of my control system may be made to clutches, for example. whereby to control the vehicle power transmitting drive at any convenient point or points. In any event, I preferably employ some form of pressure fluid operated device associated with the power transmission, such device being operated by my pressure fluid control means.

In carrying out my invention, according to one embodiment thereof, I provide a valve adapted to be operated in response to predetermined pressure of a suitable fluid acting on the valve for controlling the delivery of the pressure fluid to the drive control device aforesaid. By pumping the fluid proportionately with a part whose speed of movement varies with the vehicle speed, the valve is operated in accordance with vehicle speed to provide what may be termed a hydraulic governor.

I preferably incorporate a system of orifices associated withthe fluid delivered to the valve and from the drive control device so arranged that both the operation and release of the drive control device will take place at predetermined desired vehicle driving speeds. As an auxiliary feature, my invention further includes means under control of the vehicle driver for venting the fluid acting on the valve so that the valve may return to cut off pressure fluid delivery to the control device independently of the vehicle speed. By incorporating an oriflce in this vent I have provided a restrictive vent control on the valve return by the driver control means such that the vent will be effective to return the valve only below a predetermined vehicle speed.

A further feature of my invention resides in the provision of the aforesaid driver control means in conjunction with the vehicle throttle adjusting mechanism which usually embodies an umrem STATES PATENXT OFFICE accelerator pedal. Where my system is associated with a valve operating to effect a step-up or a faster drive in a power transmission, I have thus provided means for. returning the valve for a kick-down operation of the transmission by manipulation of the accelerator pedal provided that the vehicle speed is not excessive as where my restrictive vent or oriflce 'is employed asaforesaid. Such arrangement protects the mechanism against a down-shift in the transmission under conditions which might, excessively race the engine and otherwise be objectionable. I may also arrange the mechanism so that the valve cannot be moved under action of the pressure fluid until the accelerator pedal is approxi-.- mately fully released, the kick-down operation preferably requiring manipulation of the accelerator pedal through its throttle opening range of travel and therebeyond.

I have also provided a further driver control means which may be used as a dash control" to render the valve inoperative to supply pressure fluid to the control device.

In the more specific phases of my invention the fluid operated control valve is arranged so that it will momentarily dwell ,while travelling from a position of venting the drive control device to a second position of delivering the pressure fluid to the drive control device. As the valve starts its movement it closes the vent at the valve pressure chamber so that its movement once started is accelerated by a rise in the pressure of the fluid acting-on the valve. At the dwell point the valve delivers fluid to the drive control device to effect initial engagement thereof while restrictively venting this device to effect a smooth or soft engagement of the control device. Then the pressure of the fluid rapidly builds up and the valve completes its movement to the aforesaid second position to fully engage the control device which is preferably frictionally engaged. Even when the control device is fully engaged it is preferably restrictively vented to enable control of its release in accordance with conditions of pressure of the fluid supplied thereto.

In a modified embodiment of my invention, I have applied my fluid system to a drive control device in the form of a clutch operating between a fluid coupling and any suitable type of speed ratio transmission,

In power transmission systems embodying a fluid coupling, difficulty has .been experienced in that when the engine idles, the inherent drive or drag effect in the fluid coupling causes the vehicle to creep and is otherwise obiectionablein preventing smooth changes in the transmission mechanism. My invention provides fluid pressure means preferably operating in response to predetermined speed of the engine or input shaft for automatically controlling the drive connection between the fluid coupling and the transmission, the arrangement being such that the fluid coupling is automatically disconnected from the transmission when the engine idles and is automatically connected when the engine speeds I preferably employ an oriflce presenting a sharpedge to the fluid flow in order to minimize the eflect of temperature changes on the fluid medium. In general, any -fluid conduit oifers two classes of resistance to fluid flow therethrough, via, one being a function of the fluid viscosity and the other having to do with the kinetic effects of the fluid.

The kinetic efiects vary as the density of the liquid is changed and this is a negligible factor within the'temperature range ordinarily dealt with in automotive practice. The viscosity, on the other hand, varies greatly with thetemperature changes within this range and with liquids customarily used in pressure fluid systems for vehicle drive controls in general.

The sharp edge orifice has a minimum of length and surface over which the oilor other fluid is in shear and therefore the viscosity may vary without material variation in the flow through the oriflce. This allows a wide selection' of fluids without corresponding variation in the operating functions of the system and is important in insuring continued functioning of ,thesystem under very nearly the same conditions of vehicle or engine speed regardless of temperature variation of the fluid medium.

* Further objects and features of my invention will be more apparent as this specification progresses, reference being had to the accompanying drawings in which:

Fig. 1 is a side elevational view, somewhat diagrammatic in form, illustrating my invention applied to a motor vehicle overdrive transmission, a portion of the casing of the main speed ratio transmission being broken away to illustrate the gearing.

Fig. 2 is a detail fragmentary sectional elevational view taken as indicated by the line 2--2 of Fig. 6 illustrating the overrunning clutch which forms a direct drive releasable connection between the driving and driven shafts of the overdrive mechanism.

Fig. 3 is a detail enlarged side elevational view of a portion of the engine throttle valve adjusting and kick-down mechanism illustrated in Fig. 1.

- Fig. 4 is an enlarged sectional elevational view of the lost-motion connecting device in the throttle-operating mechanism of Fig. l.

Fig. 5 is an enlarged sectional plan view illustrating the development of a portion of the clutch teeth as seen at the section line 5-5 of Fig. 6.

Fig. 6 is a sectional elevational view through the overdrive mechanism and a portion of the main speed ratio changing transmission.

Fig. 7 is a detail sectional view illustrating the pressure fluid inlet to the motor for actuating v the pump casing broken away.

Fig.'1l is a sectional elevational view taken as indicated by line lill of Fig. 10 illustrating my pressure fluid control with the valving thereof in the position corresponding to normal direct drive for the particular transmission illustrated in Figs, 1 to 10 in association therewith.

Fig. 12 is a sectional plan view taken as indicated by line l2-i2 of Fig. 11 illustrating the kick-down valve in its Fig. 11 position.

Fig. 13 is a sectional elevational view taken as indicated by line i3-l3 of Fig. 11. g

. Fig. 14 is a sectional elevational view taken as indicated by line Il-M of Fig. 11.

Fig. 15 is a sectional plan view taken as indicated by line i5|5 of Fig. 11 illustrating the dash control valve in its Fig. 11 position.

Fig. 16 is a sectional elevational view taken as indicated by line IS-IB of Fig. 11.

Fig. 17 is a view of the Fig. 11 pressure fluid control showing the main control valve at its momentary dwell point in moving from its Fig. 11 position to its Fig. 18 position and illustrating the kick-down valve in its position corresponding to full release of the accelerator pedal.

Fig. 18 is a view of a portion of the Fig. 11'

pressure fluid control showing the main control valve in its position during operation of the overdrive.

Fig. 19 is a view of theFig. 11 pressure fluid control showing the kick-down valve in its position corresponding to full depression of the accelerator pedal beyond its wide open throttle position, the main control valve being shown in its'restored Fig. 11 position releasing the overdrive.

Fig. 20 is a view generally similar to Fig. 11 illustrating a modified form of my invention.

Fig, 21 15 a view generally similar to Fig. 3 but illustrating a modified arrangement of accelerator pedal kick-down control.

Fig. 22 is a side elevational view of a further power transmission system differing from the Fig. 1 system and utilizing the Fig. 20 form of my pressure fluid control with slight modification, parts of the operating mechanism being shown in sectional elevation.

Fig. 23 is a fragmentary sectional elevational view of the driver controlled valve employed with the Fig. 22 system.

Fig. 24 is a detail sectional plan view taken as indicated by line 24-24 of Fig. 23.

Referring to the drawings, I have illustrated my invention in conjunction with a change speed transmission and more particularly in Figs. 1 to 21 in conjunction with an overdrive mechanism of the general type disclosed and claimed in th@ copending application of Neracher et al.,

Serial No. 222,006 filed July 29, 1938. However,

I desire to point out that my invention may be used with a variety of drive control systems afas des fording overdrive or other speed ratio of drive as may be desired "including a direct or one-toup or step-down speed ratios may be controlled as will presently be more apparent from the following illustrative description of the principles of my invention.

As an example of using my invention, I have illustrated the overdriving mechanism A interp sed between a speed ratio changing main transmission B and a driven shaft 26, and its extension 26, the latter extending rearwardly to drive the rear wheels (not shown) of the motor car or vehicle in the usual well known manner, it being understood that I have elected to show my invention in association with a motor vehicle drive although in its broader aspects. it is not necessarily limited thereto. The customary propeller shaft brake drum 21 is illustrated between. shafts 26 and 26 as comprising ,a part of the drive from the overdriving mechanism A to the vehicle.

The illustrated driving mechanism may be used to advantage at various other points in the line of general power transmission between the vehic-le engine C and the driven wheels, or between driving and driven means such as shafts of other types of devices. In accordance with customary practice, the drive from engine C to the main transmission B is controlled by a clutch D of any suitable type, this clutch transmitting the drive to the main transmission by a shaft 28.

The transmission B may be of any suitable type, such as the conventional selector type operated in the well known manner by manipulation of the gear shift lever 28 and the usual selector.

controls, whereby the various adjustments may be made to the transmission in order to provide forwardly driving speed ratios and a reverse drive through the transmission.

Inasmuch as the type of transmission illustrated at B is well known in the art, I have shown only a portion of the operating mechanism in Figs. 1 and 6. Shaft 28 carries the countershaft driving pinion 30 and also the direct drive clutch teeth 31 pinion 30 meshing with the driving 'gear 32 of the countershaft clutch gearing which further includes a second speed drive gear 33, a low speed drive gear 34, and a gear 35 in constant mesh with a reverse idler gear 36. Loosely mounted on the transmission power take-off shaft 31 for rotation relative to this shaft, is the usual second. speed gear 38 in constant mesh with the countershaft gear 33, a set of second speed clutch teeth 38 being driven with gear 38.

Splined on the shaft 31 for shifting movement along this shaft is the low and reverse gear 40 shiftable by a fork 41 under control of the gear shift lever 28. When the gear 40 is shifted forwardly into mesh with countershaft gear 34, shaft 31 will be driven from shaft 28 in a forward low speed ratio drive through the gear train 30, 32, 34 and 40. When the gear 48 is shifted rearwardly to mesh with the reverse idler gear 36, shaft 21 will be driven backwards or in reverse relative to the forward direction of rotation of the shaft 28 through the gear train 36. 32, 35, 36 and 40.

In order to selectively drive shaft 31 in the second or intermediate speed ratio, and also in a direct drive, the usual shiftable clutch 42 is provided operable by' the fork 43 under control of the gear shift lever- 28, thi clutch 42 being drivingly connected to the shaft" and adapted for" selective forward and rearward shifting movements respectively to clutch with the direct drive clutch teeth 3| or the second speed drive clutch teeth 38. During the direct drive, with the partsas shown in Fig. 1, shaft 28- drives the shaft 31 by reason of engagement of clutch teeth 3| with the corresponding teeth of the shiftable clutch 42. During the second speed drive the shaft 31 is driven at a reduction speed ratio greater than that provided by the low speed ratio drive, by reason of the gear train 30, 32, 33, 382, clutch teeth 33 and shiftable clutch member The main transmission B has the aforesaid gearing disposed within a casing 44 which provides a reservoir or sump 45 for storing a suitable lubricating oil which is p eferabl circulated, as will be presently more apparent, between the transmission B and the overdriving mechanism A and this lubricating oil is preferably used as the fluid medium for effecting operation of the secondary controlling means for the overdriving mechanism. The transmission casing 44 is formed with a rear annular wall 46 secured by fasteners 41 to the forward wall or flange 48 of the casing 48 for containing the overdriving mechanism A. Secured between walls 46 and 48 there is located an intermediate member 60.

The transmission shaft 31 is the driving shaft for the overdrive mechanism A and is joumalled in a bearing 5| carried by the intermediate member 60, the shaft 31 having a rearward driving extension 52 which projects into the overdrive casing 48 and which is formed with splines 62.

Engaging splines 52 at the rear end of driving shaft extension 52, is the inner member 63 of an overrunning clutch E which provides a releasable forward direct driving means from shaft 31 to the drive: shaft 25. The overrunning clutch functions only at such times when the two-way direct drive means does not operate for any reason, as will presently be apparent. Normally, this overrunning clutch E plays a very minor part in the mechanism. As best shown in Figs. 2 and 6, the inner member 53 is formed with the usual cam faces 54 engaged by clutching rollers 65, the rollers being spaced by the usual cage 66. The outer member of the overrunning clutch E comprises a cylinder 51 formed as an enlarged for-' ward projection of the driven shaft 25. When the driving .shaft 31 has a forward direction of rotation imparted thereto (clockwise looking front to rear) and with the overdriving mechanism inoperative, the rollers 55 will be wedged between the inner and outer members 53 and 61 respectively of the overrunning clutch E so that the driven shaft 25 will be driven in a forward direction with the driving shaft 31. However, in the event that the driving shaft tends t slow down relative to the driven shaft, or in the event that the driven shaft tends to rotate forwardly faster than the driving shaft, the rollers 55 will be released from wedging action and such tendencies of the shafts to rotate relatively to one another will be readily accommodated.

The mechanism A is arranged to provide a plurality of speed ratio drives between driving shaft 31 and driven shaft 25 by providing a relatively slow speed drive which is a direct or 1 to 1 ratio drive and a relatively fast drive which provides an overdrive whereby the driven shaft is rotated faster than the speed of the driving shaft. Planetary gearing is preferred because of the recognized advantages of quietness of operation, simplicity, etc., although if desired, other forms of gearing may be employed.

The planetary gearing comprises an input planet pinion carrier structure 60 adapted to be driven directed from driving shaft 31, thi rier structure being conveniently formed as an extension of the overrunning clutch cam member 53. The carrier structure is provided with a forward carrier portion 6| connected to the portion 80 by a plurality of axle shafts 62 and spacing assemblies 83, one of these axles and spacing assemblies being illustrated in Fig. 6.

Rotatably journalled on each axle 62 is a planet pinion 84 meshing with an internal gear 85 drivingly secured at the splines 66 with a flanged extension 81 of the aforesaid driven shaft forward extension 51 of the overrunning clutch E. The planet pinions 64 also mesh with a hollow sun gear 68 having an internal lining of bearing material 69 whereby the sun gear is loosely Journalled on the driving shaft extension 52 forwardly of the spines 52. The sun gear has a forwardly extending controlling hub 10 formed with axially extending splines Il slidably engaging the internal splines 12 of a shiftable drive controlling sleeve 13 formed with external clutch teeth 14 adapted to clutchingly engage corresponding internal teeth I5 (Fig. 5) carried by the carrier member 6i.

When the sleeve 13 moves rearwardly to clutch with the carrier portion 6i, the teeth 14 and 15 are so constructed that they may relatively overrun without danger of injuring the teeth which are constructed so that they will engage only when the mating clutch teeth are rotated synchronously. Thus the end faces of teeth 14 are inclined at I6 and the forward ends of teeth 15 are correspondingly inclined at ll. This inclination is preferably in the neighborhood of five degrees, although for purposes of illustration, the inclination has been exaggerated in Fig. 5 and the inclination may be in the form of a threadlike spiral in order to insure full surface contact at the ends of the teeth or the end faces may be substantially flat. The direction of inclination is such as to permit the carrier and teeth 15 to rotate forwardly at a speed faster than forward rotation of the sun gear 68 and sleeve 13 carried therewith, the teeth 15 camming over the teeth 14.

In order to provide means for yieldingly urging rearward movement of sleeve 13 to effect clutching thereof with the carrier 6i, yielding means is provided in the form of a spring 18 acting between an abutment l9 and a disc 80, the inner portion of which is fixed to sleeve 13 by a splined engagement at 8! therewith. This disc 80 provides a braking element for arresting rotation of sun gear 68 when the sleeve 13 is moved forwardly to disengage clutch teeth 14 and 15 in order to effect the overdrive between driving shaft 31 and driven shaft 25. In conjunction with my invention I provide means preferably operated by pressure fluid for shifting the disc 80 and sleeve 13 forwardly in opposition to spring 18, the arrangement being such that this shifting action of the sleeve will take place even during a full torque application of the engine C in driving the driven shaft 25 directly from shaft 31 without requiring reduction in the torque of the engine as has heretofore been common in connection with transmissions employing overdrive gearing. By employing pressure fluid controlled in a novel manner presently described I obtain the desired relatively high pressure required to shift the sleeve 18 forwardly under the aforesaid conditions and also to hold the sun gear 88 against rotation while taking the drive reaction of the overdrive.

The pressure fluid operated means comprises a braking device. generally designated at 1'', adapted to be actuated to brake the disc by pressure fluid motor, designated as G. The braking device F comprises a pressure plate 82 externally splined at 88 to engage the internal splines 84 formed on the casing 48, the splines being interrupted at the outwardly extending casing pockets 8! one of which is shown in Fig. 6 and into each of which projects the finger 88 which is welded to the pressure plate 82.

A coil spring 81 acts in each pocket 85 between the intermediate member 50 and a flnger 88 to yieldingly urge the pressure plate 82 rearwardly in its released position, this pressure plate carrying on its forward face a ring of friction braking material 88 engageable with the rear face of the disc 80. The forward face of this disc was adapted to engage the braking material 88 fixed to the intermediate member 50.

The motor G comprises an annular cylinder formed as a part of the casing structure 49 and opening forwardly to slidably receive the annular piston assembly 9| which engages the pressure plate 82 and is adapted to be urged forwardly by pressure fluid. Thus when pressure fluid is introduced to cylinder 90 at the rear of piston 9|, as will presently be apparent, this piston is moved forwardly in cylinder 90, causing the pressure plate 82 to slide forwardly in the splines 84 into engagement with disc 80, this disc and the sleeve 13 then moving forwardly as a unit to. disengage clutch teeth I4 from the carrier teeth 15 and to bring the disc 80 into braking engagement with the friction material 89 against the action of the springs 81 and I8 thereby securely holding the sun gear 68 against rotation as lon as the fluid under the required pressure is being admitted to the cylinder 90.

When the pressure of the fluid in cylinder 90 is relieved or when the pressure drops below that required to maintain brake F in operation, the springs 18 and 8'! will operate to return the parts to their illustrated positions in Fig. 6, the spring 81 acting to separate the friction material 88 from the disc 80 while the spring 18 yieldingly urges clutching engagement of teeth 14 with teeth 15.

In the operation of the mechanism as thus far described and assuming a forward rotation of driving shaft 31 and with the parts positioned as in Fig. 6, a direct drive will take place to drive shaft 25 because sleeve I3 is operating to clutch the sun gear 68 with carrier 6| thereby locking the planetary gear train and causing the same to revolve as a unit with the driving and driven shafts, thus providing a two-way direct drive.

Assuming that while the direct drive is taking place by the application of torque from the engine, pressure fluid is introduced to cylinder 90. This will cause operation of motor G as aforesaid to shift sleeve 13 forwardly thereby disengaging clutch teeth 14 and 15 hr releasing the sun gear 68 from the carrier 6|, the sun gear then being arrested against rotation by operation of the braking device F which will produce the overdrive. At such time the planet pinions 64 will be driven forwardly around the fixed sun gear 88 thereby causing the driven shaft 25 to rotate forwardly faster than the speed of the driving shaft,clutchEoverrunnlng.- 9

Whenever the pressure fluid drops in cylinder ll below the critical pressure required to operate braking device I", this braking device. will be released and a step-down will take place in mechanism A by changing the drive therethroush from the overdrive to a direct drive. This change in speed ratio drive is also adapted to take place even in times when the engine is delivering its maximum torque and assuming that the cylinder is vented under such conditions, it will be apparent that braking device F will be released. spring 18 moving sleeve 13 rearwardly. When the braking device 1'' releases, the sun gear 68 and sleeve 18 which were previously held against rotation now quickly accelerate forwardly at the time that sleeve 13 is shifted rearwardly. It will frequently occur that the sleeve 13 will be accelerated to a speed equal to that of carrier 6| so that the sleeve will clutch with the carrier to provide the direct drive under the aforesaid assumed conditions. However, should the teeth 14 not clutch with the teeth 15, the sleeve 13 cannot rotate forwardly faster than carrier 6| because overrunning clutch E will immediately come into operation to establish the direct drive from driving shaft 31 to driven shaft 25.

When the overrunning clutch thus operates, the faces 16 of teeth 14 will be engaged with the faces 11 of teeth 16 and the next time that-the driver partially releases the usual accelerator pedal to allow the driven shaft to overrun the driving shaft, spring 18 has suflicient strength that it will then act to force the teeth 14 into clutching engagement with teeth" as soon as teeth ,14 slide oif the faces 11 of teeth 15. During this overrunning action the sun gear and sleeve 13 will slow down at a faster rate than the carrier I so that the relative change in speeds of teeth 14 and 15 is not abrupt but is sufliciently gradual to permit clutching engagement of these teeth under these conditions.

Experience has been that it is impossible, with the parts properly proportioned, to cause the teeth 14 to ratchet over the teeth 15 during this overrunning action because clutching of these teeth will immediately take place. However, if for any reason such overrunning action of the teeth took place, clutching engagement of these teeth would obviously take place the next time that the engine is accelerated to drive the car because the inclined faces 11 would then guide the faces 18 of teeth 14 into clutching engagement with the teeth 15, as will be readily understood.

In driving the vehicle in reverse by theaforesaid manipulation of shift lever 29 to engage gear 40 with the reverse idler gear 36, the mechanism operates so that it does not require any lockout means for the overrunning clutch E. Before driving in reverse the vehicle is obviously :Iirst brought to a standstill and as I preferably supply pressure fluid to cylinder 90 from a pumping means driven from the driven shaft 25, or otherwise at a speed proportionate with the vehicle speed, it will be apparent that when the vehicle pump is at rest, the pump will not operate and the pressure fluid will drop at cylinder 00, thereby releasing braking means F to allow the sleeve 13 to move rearwardly and clutch with the carrier CI to enable the reverse drive from shaft 31 to driven shaft 25. If the teeth 14 should not clutch with the teeth 15 but merely engage the faces 11, then as soon as the driving shaft 31 starts to rotate backwards for the reversedrlve, the sun gear 00 and sleeve 13 will rotate backwards faster than backward rotation of carrier BI and the spring 18 will immediately cause the teeth 14 to clutch with the teeth 15 Just as soon as teeth 14 slide oif the faces 11.

I will now describe the pressure fluid pumping means for supplying pressure fluid to the motor G, this means being preferably so arranged that when the vehicle is accelerated in the direct drive up to a predetermined desired speed, the pump will build up suincient pressure to enable operation of motor G to eifect the change in mechanism A from the direct drive to the overdrive. Likewise when' the speed of travel of the motor vehicle drops below a predetermined desired critical speed, then the pressure of the nuid at motor G will drop causing the overdrive to be released automatically and the direct drive to immediately take place as the engine speeds up, either by engagement of the overrunning clutch E or. by clutching the sun gear with the carrier, as aforesaid.

The pumping means, generally designated at J, is preferably driven directly from driven shaft 15 although, if desired, the pumping means may be driven with any part which is orivingiy connected to this shaft so'as to produce pressure in response to motion-of the vehicle. This pumping means is carried in a casing 92 secured at the rear of casing 49 and comprises a driving pump member 83 (Figs. 6 and lo) drivingly connected by ball 94 with the driven shait 25, the member as having tooth-like projections 9a of a well known type adapted for driving engagement with corresponding recesses 96 in the pump driven member 91 which is eccentrically mounted in the casing 02, the recesses being one more in number than the teeth as is common with the type or pump illustrated. A closure plate 98 is secured by rasteners 98 to the casing 92 and engages the forward faces of the pump members in and 91.

The casing 92 is provided with the crescentshaped intake and pressure dehvery ports luv and IIII respectively, the intake port (rigs. b and 8) communicating with a downwardly extending passage I02 formed in casing 81 and which opens forwardly at its lower end with an intake chamber portion I03 formed by the bottom portion I04 of casing 49 and the chamber wall I05 cast therewith, the chamber portion I03 communicating freely at its forward outlet I 06 with the reservoir or sump I01 in the casing 49. This reservoir preferably communicates by the system of passages at I08 through the casings 44 and 49 and the intermediate member 50, with the reservoir 45 in the main transmission B so that the lubricating oil stored therein may pass ireely between the transmlssion mechanisms B and A.

The inlet chamber portion I03 functions, as will presently be apparent, to circulate the oil to the pump J from the motor G and also from the pump without first flowing to the motor G such additional oil as may be necessary being drawn from the reservoir I01. This has a particular advantage, especially in cold weather, in facilitating operation of the mechanism by quickly warmingup" only a portion of the oil which is discharged by the pump J and led back to the pump in advance of warming-up all of the oil in the reservoirs 45 and I01. The oil is originally drawn from chamber I01 and flows through passage I02 to the pump inlet I00, the pump delivering th oil under pressure to the outlet port IOI whence the oil is delivered (Figs. 8 and 9) downwardly through a discharge passage I03 formed in casing 32 and then forwardly at the bottom of the passageto a delivery passage I I formed in casing 40.

The delivery passage IIO (Figs. 8 and extends transversely of the mechanism A to the side thereof opposite that which is viewed in Fig. 1

for delivery at III to the inlet II2 of my valving means K which is adapted to control the delivery of the pressure fluid from the pump to the motor G and also the venting of the fluid from the motor G directly back to the chamber portion I03 for recirculation to the pump J. Referring to Fig. 6,

the casing 32 is adapted to receive the usual speedometer gears II3 and Ill.

Referring to Figs. 6 and 9. I have providedmeans for relieving excess pressure fluid delivered by the pump comprising a valve casing I I1 having a passage II3 open to the pressure delivery passage I03, the casing II'I being formed with a seat III! for a ball valve I yieldingly urged toward seat I I3 by a spring I2I whose compression is ad- Justably controlled by a threaded abutment plug means is, however, so arranged as not to function when the vehicle is travelling above a predetermined speed. My arrangement enables the use of the overdrive'for city driving as well as for country driving and where my invention is used in conjunction with an overdrive I therefore preferably arrange the parts so that the overdrive will automatically take place at a car speed of to 32 miles per hour, by way of example, the critical speed being preferably arranged at some definite relatively low vehicle speed in order to obtain the beneflts of city driving. If desired, the parts may be arranged to provide for the overdrive at much higher car speeds in the neighborhood of 40 or 45 miles per hour, for example, or at any other desired speeds as will be presently more apparent.

Referring to Figs. 6, 7 and 11, the pressure fluid from the valving means K is delivered to the motor G by a port I25 which leads transversely inwardly of the transmission for delivery at I26 to a longitudinally extending passage I21 and thence through the communicating curved passage I23 for delivery at the rear end of cylinder 90. A plug I29 is secured by a fastener I30, this plug closing off the forward portion of the passage I21 which may be conveniently drilled from the forward end of the casing 49.

When the valving means K is operated, as will presentlybe apparent, to relieve the fluid pressure at motor G, then the fluid drains back through passages I28, I21 to the valve from whence the fluid drains through a port I3I and the inwardly extending drain passage I32 and thence through the rearwardly extending passage I33 which opens at I34 (Figs. 6 and 10) adjacent the inlet I06 of chamber portion I03 for recirculation to the pump J as aforesaid.

Referring to my valving means K I have illustrated a pressure fluid control device embodying a variety of interrelated functions of control for the change speed device A and while it is not necessary to include all of these functions, as will presently be more apparent, I have elected to illustrate these various functions inasmuch as they produce a novel and desirable control on the aforesaid change speed mechanism.

In general, the valving means Kcomprises a main valve adapted for automatic operation in response to a predetermined pressure of fluid 'delivered by the pump J for causing the valve to move with accelerated or snap actionfrom a first position corresponding to the relatively slow speed drive through the mechanism A, viz., the direct drive, to a second position corresponding to the relatively fast speed drive which in the present instance is the overdrive.

I have also provided additional means in the form of a pair of valves each being adapted for operation under control of the vehicle driver independently ofeach other and independently. of the movement of the main automatic valve. One of these driver-controlled valves may be conveniently termed a dash control and is adapted for manipulation by the vehicle driver at the dash or other convenient point and has the function-of either allowing the main automatic valve to move in response to pressure fluid acti'ng thereon or else' to prevent movement thereof into the overdrive position under all conditions.

The other of the aforesaid driver-operated valves is arranged in series with the main valve and the dash control valve and by preference is operated in response to manipulation of the engine throttle valve by a suitable operating means which functions in response to manipulation of the usual accelerator pedal. 1 have so arranged this valve that it modifies the operation of the main valve both in controlling the step-up in the driving mechanism A in going from direct to overdrive and also for the step-down change in the drive in going from overdrive back to direct.

One preferred arrangement which I have illustrated in connection with the accelerator pedal operated valve is such that the main valve cannot move into its overdrive position until the accelerator pedal is approximately fully released. This has the advantage of preventing undesired fluctuations in the manipulation of the driving mechanism A and also insures a desirable slowing down of the engine when the overdrive is manipulated to effect a step-up in the drive and thereby assisting in the provision of a cushioning effect free from shock or jolt. A further function of the accelerator pedal controlled valve has to do with manipulating the mechanism A from overdrive back to direct drive independently of the pressure fluid which at such time may be such as to tend to hold the main valve in its overdrive position. This function may be termed a kick-down control for the mechanism A and I have so arranged the mechanism as to require the accelerator pedal to be depressed into a kick-down range of movement beyond the position of the accelerator pedal corresponding to wide open throttle by the provision of the suitable mechanism which accommodates an overtravelling' of the accelerator pedal. I have also provided an arrangement such that when the vehicle is exceeding a predetermined relatively high speed accompanied by a relatively great discharge of fluid from the pump J, the mechanism A will not be manipulated for the change from overdrive back to direct even though the accelerator pedal is depressed to its of the kick-down position. This provides a feature of flow of fluid from passage III to passage "2.4

safety and under many conditions is preferred.

By arranging the kick-down control to function when the engine throttle valve is in its wide open throttle position. the mechanism A is manipulated from overdrive to direct accompanied by a natural tendency of the engine to speed up, thereby likewise assisting in the cushioning action of this speed ratio change just as in the case akforesaid change from direct to overdrive. The kl -down control will furthermore operate as a result of thenatural impulse of the vehicle driver when faster acceleration or more favorable driving power is desired since under such conditions the driver will naturally depress the accelerator pedal. This kick-down control is very desirable in overtaking and passing other vehicles on the road and also to assist in climbing steep hills under the more favorable driving ratio of direct as compared with overdrive. Once the kick-down functions to change from overdrive to direct, my arrangement is such that the overdrive is not restored until the accelerator pedal is substantially fully released and' The orifice I55 provides a restrictive vent for the 'fluid in the annular groove I45 for purposes which will be presently more apparent.

The annular groove I46 as best shown in Fig. 13 is in constant communication with the aforesaid fluid delivery passage I25 of the casing I35, this passage in turn communicating with the delivery passage I26 for supplying the pressure fluid to the motor G for operating the brake F. The annular groove I41. isin continuous communication with the aforesaid relief passage III of casing I35, this passage in turn communieating. with the aforesaid passage I32 which conducts fluid back to the intake chamber portion by the annular groove I41 is restrictively vented the following detailed description of the illustrated embodiment thereof. Referring particularly to Fig. 11 and also to Figs. 12 to 19, the valving means comprises a main casing I adapted to be secured by fasteners I36 to the side of the mechanism A (see also Figs. 1, 8 and 10). The casing I35 has a front cover I31 secured thereto by fasteners I33 and I39, there being interposed between the cover and the casing a sealing plate I40.

The casing I35 is formed with a longitudinally extending bore I4I opening forwardly to the plate 0- and having a rear shoulder I42 and counterbore pressure chamber I43 which opens to the aforesaid delivery passage II2 leading from the exhaust port IOI of the pump J. Fixed within the bore I is a sleeve I44 which is disposed between plate I and shoulder I42, this sleeve being formed with the longitudinally spaced external annular fluid conducting grooves I46, I46 and I41. opened radially inwardly'through the sleeve I44 by reason of the ports-I48 and the annular groove I46opens inwardly through ports I49. The annular groove I41 is also opened inwardly of the sleeve by one or more ports I50.

The annular groove I is in continuous communication with an inwardly extending relief or venting passage I5I which is formed in the casing I35 and which communicates with a vent I passage I52 formed in the casing 49 of the mechanism A and is adapted to deliver oil from the annular groove I45 to the discharge I53 (Fig. 6) located in the inlet chamber portion I03 so that the fiuid discharged from the port I53 will be immediately circulated through passage I02 to the intake port I00 of the pump J. At some suitable point in the flow of the fiui from the annular groove I45 back to the discharge I53, I provide an orifice preferably in the form of a thin plate illustrated at I54 in Fig. 14 between casings I35 and 49. This plate has a metering opening I55 preferably in the form of a frusto-cone so as to present a sharp edge and a minimum amount of surface to the along its line of fluid discharge. The orifice I51 is appreciably smaller than the aforesaid orifice I55 in order to effect certain desirable functions in the manipulation of the mechanism A as will be presently described.

Slidably disposed within the sleeve I44 is the main automatic valve L, this valve being illustrated in Fig. 11 in the direct drive position corresponding to the position of the parts of mechanism A as illustrated in Fig. 6. In this position the valve L is urged rearwardly against the shoulder I42 by a preloaded spring I56 which the valve L is provided with a relatively long The annular groove I45 is 'annular port or groove I62 formed externally of the valve and, with the valve positioned as in Fig. 11, this groove I62 establishes communication between ports I49 and I50 thereby restrictively venting the motor G through the following system of passages and ports, namely, I26, I21, I26, I25, I46, I49, I62, I50, I41, I3I, thence through the orifice I51 and passage I32 to the outlet at I34.

Spaced forwardly from the annular groove I62, the valve L is' provided with an annular pressure relief groove I63 communicating inwardly through the radial passages I64 with the forward low pressure valve bore I65 open for open to the bore I65 through a small lead passage I66 formed in the thimble I69 which is fixed between the bores.

When the valve L moves to its forward terminal position against the stop I61 then at such time the annular groove I63 registers with a vent passage I10 which extends inwardly through the casings I35 and 49 and discharge at I1I (Fig. 6) so that the oil flowing, inwardly from the dis- In order to limit the forward v charge "I will collect in the oil reservoir I81 in the bottom portion I84 of the casing 49.

The sleeve I44 is formed, with an upwardly extending relief passage I12 which, with the parts positioned as in Fig. 11, places the relief chamber I88 in communication with acorresponding passage I13 of the casing I35 adapted to conduct the oil under control of the kick-down valve M upwardly through the casing passage I14 and thencevunder control of the dash valve N to a drain or'relief passage I18 which leads inwardly through casings I35 and 49 for. diserator pedal is depressed beyond the wide open charge at I11 so that the oil will flow into the storage reservoir I81.

Referring now to the dash control and the valve N, this valve is sli-dably disposed in the bore I18 of easing I35, the here being rearwardly closed at I19 at which point there is located a vent I88 similar to the vent I18 for draining any oil which may be trapped rearwardly of the valve N back to the reservoir I81. This vent I88, as shown in Fig. 13, communicates with the reservoir through a passage I8I of easing I35 and thence through the passage I82 formed in the .casing 49 to the discharge or outlet I83 (Fig. 6).

The valve N is formed with the heads I84 and I85 slidable in bore I18 and between these heads this valve is provided with an annular groove I88 which, with the valve positioned as in Fig. 11, establishes communication between passage I14 and the vent at I18. Fixed to the head I85 is the rear end portion I81 of a Bowden wire mechanism I88 arranged to operate through the plate I48 and moving the valve from the Fig. 11 position to a position forwardly thereof when the head I84 will close the passage I14 and prevent the escape of fluid from this passage to the vent I18.

In order to conveniently control the operation of valve N, I have extended the Bowden wire I88 to the usual dash or instrument panel I89 (Fig. l) where the Bowden wire terminates in a knob or a handle I98 adapted to be pulled by the driver. In order to releasably hold the valve N selectively in its two positions of adjustment, I have provided a spring pressed ball detent I9I selectively engageable with grooves I92 or I93 formed in the plunger portion I94 of the Bowden wire mechanism adjacent the knob I98 and slidable in the guide bracket I95 carried by the panel I89. In the Fig. 1 'position, the knob is positioned inwardly corresponding to the Fig. 11 position of valve N and when the knob is pulled by the vehicle driver to register grooves I93 with the ball detent I9'I, then the valve head I84 will close the passage I14.

Referring now particularly to Figs. 1, 3, 4, 11 and 12, I will next describe the kick-down valve M and the means for controlling the operation of this valve in response to manipulation of the engine throttle valve by the vehicle driver. The valve M comprises a pair of longitudinally spaced heads I96 and I91 slidably fitting the casing bore I98. The head I98 is formed with an annular groove I99 which is adapted to establish communication between passages I13 and I14 only when the accelerator pedal is approximately fully released. At other times when the accelerator pedal occupies a, position of throttle valve opening or when it is manipulated for the kickdown position, the annular groove I99 is not registered with passages I13 and I14 at which time the head I98 shuts oif communication between these passages thereby closing the chamthrottle position for the kick-down operation. At such time the valve M is moved rearward]? to register an annular groove 282 formed in the head I81 with the aforesaid branch passage 288. At the same time the annular groove 282 communicates with a relief passage 283 which extends inwardly of the casing I and communi cates. with a passage 284 formed in the easina 48 so that the fluid passing through these passages is discharged through an outlet 285 for return to the reservoir I81 preferably at the point in the general neighborhoodof the port 7 I 88 to the intake chamber I83.

The relief or vent thus provided from branch passage 288 to the outlet 285 is preferably of the orifice controlled type so as to provide a restrictive vent and to this end I have located a further thin plate oriflce 286' between the passages 283 and 284, this plate having an opening 281 of the aforesaid type presenting a, sharp edge toward the flow of fluid. The opening 281 may be approximately the same size as the opening I55 of the orifice plate I54 or it may be slightly larger or smaller than the latter opening in order to accomplish the illustrated functions of my controlling mechanism. The opening I51 of the orifice plate I58 is, however, preferably smaller than the oriflce I so as to obtain the decided difference in the motor vehicle speed at which the valve L will return from the Fig. 18 position to the Fig. 11 position in comparison with the vehicle speed at which the valve L will move forwardly from the Fig. 11 position as will be presently more apparent.

At the forward end of the bore I98 the casing I35 is formed with an enlarged extension bore 288 Slidably receiving a cylindrical member 289 having an annular flange or shoulder 2I8 yieldingly urged rearwardly against the casing shoulder 2| I by a spring 2 I2 which acts at its forward end against the plate I48. Whenever the accelerator pedal is depressed at any point throughout its throttle valve adjusting range, the spring 2! 2 maintains the cylindrical member 289 against the shoulder 2I I and the valve M is in the Fig. 11

her I88 against escape of the fluid which is 1.

position. The valve M has a forward terminal forked portion 2I3 pivotally connected by a pin 2I4 with a, link 2I5 which extends forwardly through the plate I48 for pivotal connection by a pin 2I8 with a swinging plate member 2I1.

In order to vent the bore 288 to facilitate forward movement of the valve M from the Fig. 11 position thereof to the position illustrated in Fig. 1'7, which is brought about by fully releasing the accelerator pedal, the bore 288 opens into a passage 2I8 which extends inwardly of the casing I35. and communicates with an upwardlyextending oblique passage 2I9 which in turn opens into the aforesaid vent I18 leading to the drain outlet I11. may be similarly vented in order to insure proper ftmzzioning of the parts as will be readily unders o The plate H1 is fixed to a pivot pin 228 rockingly supported in the cover I31 and likewise secured to this pivot pin is a downwardly extending lever 22I having pivotal connection at 222 with the rear end of a Bowden wire mechanism 223.

Other bores or chambers The forward end 01 this Bowden wire mechanism has connection at 224 with the forwardly extending end of a lever 225.

In order to stabilize the action of the valve M- particularly in the Fig. 11 position thereof against any tendency to move rearwardlyor to the left as viewed in Fig. 11, I have illustrated a detent means in the form of a cam lever 225 adapted to act on a roller 221 supported at 228 by the plate 211. The lever 225 is ro'ckingly mounted by a pin 229 supported in the cover I31 and has a downwardly extending end'portion 230 adapted to strike the cover portion at 231 in order to limit counterclockwise swinging of the lever 226 under the action of the detent spring 232.-

Referring now particularly to Figs. 1, 3 and 4, the lever 225 has its rearwardly extending end fixed to a shaft 233 which extends transversely of the vehicle beneath the usual toe board 234 and is suitably supported by the journalling brackets, one of which is illustrated in Fig. 3 at 235. Likewise fixed to the shaft 233 there is a downwardly extending sector 235 having an arcuate slot 23! whose center is at the axis of the shaft 233. This slot 231' slidably receives a pin 238 which is carried by and projects laterally from the lever 239 which is loosely supported at its upper end on the shaft 233.

At its lower end the lever 239 has articulated connection at 242 with a rearwardly extending link 2 and also with a forwardly extendinglink 242. The link 2 extends through an opening 243 in the toe board 234 and is connected at 244 with the accelerator pedal 245 yieldingly urged to its fully released position indicated at 245 by a spring 2 31.

In Fig. 3 I have illustrated several positions of the accelerator pedal 245 corresponding to functions of the control mechanism. Thus when the accelerator pedal occupies the position illustrated at 245, the engine throttle valve is wide open, suitable means being provided to accommodate overtravelling of the accelerator pedal beyond this wide open throttle position 258 for the kick-down operation at which time the accelerator pedal is moved to the position indicated at 245. The solid line showing of the accelerator pedal in Fig. 3 corresponds approximately to half throttle opening and when the accelerator pedal is released to the position indicated at 250 the arrangement is such that the kick-down valve M is about to be moved forwardly and does not move from the Fig. 11 position to the Fig. 17 position when the accelerator pedal is moved from the position 255 to the fully released position 2&5.

The arcuate slot 237 is of such length that when the accelerator pedal occupies the position 255 then the pin 238 engages the rear end of the slot so that when the accelerator pedal moves from the position 255 to the position 245, the segment 236 is picked up by the lever 239 and moved from the Fig. 3 position to the position indicated at 25!, thereby causing the lever 225 to thrust through the Bowden wire mechanism 223 for moving the valve M forwardly from the Fig. 11 position to the Fig. 17 position. The slot 231 is also so arranged that when the accelerator pedal is depressed to the position 245 the pin 238 engages the forward end of this slot and when the accelerator pedal is further depressed to the kick-down position 249 the lever 239 then picks up the sector 235 and moves the same from the Fig. 3 position to the position illustrated at 252. During this latter movement of pull through the Bowden wire mechanism 223 in moving the kick-down valve M from the Fig. 11 position to the Fig. :19 position.

' The link 242 extends forwardly for connection with the engine throttle valve through a lost motion device best illustrated in Fig. 4 which acts as a rigid connection when the accelerator pedal is operated throughout its throttle valve adjusting range but which allows the accelerator pedal to overtravel the throttle valve when the accelerator pedal moves from the wide open throttle position 248 to the kick-down position 243.

In Fig. 1 the engine 0 is illustrated as having the customary intake manifold 253 incorporating a riser 254 from the carburetor 255, the cus= tomary butterfly throttle valve 255 being operable by a lever 25?. a stop 258 is adapted to engage the lever 25? when the throttle valve is in its wide open position. The lower end of lever 25? is pivotally connected by a pin 25!! with a guide block 255 having a bore 25! slidably receiving the forward end of link 242.

A bracket 262 is secured to the forward end of block 265 and has a rear abutment flange 253 through which the link 242 slides, the latter link having a collar 264 fixed thereto and engageable with the forward face of the flange 263. A spring 255 acts between block 260 and collar 264 and is of sufficient strength to normally hold the parts 260 and 242 in their positions illustrated in Fig. 4,

the spring being compressed to allow the link 2423 to slide forwardly in the bore 25E of block 265 when the lever 25? is engaged with the stop 255 and when the accelerator pedal is operated to the aforesaid kick-down position 245. The spring 265 also has the function of preventing accidental kick-down of the acceleratorpedal because of the resistance which it oflers to movement of the accelerator pedal through the kick-down range over and above the resistance offered by the accelerator pedal return spring 259.

In describing the operation of the mechanism, I will assume, for purposes of illustration, that it is desired to provided for engagement of the transmission control device at brake F when the car registers a speed of 30 miles per hour and that once the brake is actuated it is desired to provide for automatic release thereof when the car slows down to 20 miles per hour unless the brake F is released sooner by the kick-down operation and that in such event the kick-down will not operate to effect a change in transmis= sion A from overdrive to direct drive in the event that the car speed at the time of attempted kickdown exceeds 60 miles per hour. These figures are, of course, given entirely by way of example and may be varied if desired bychanging the capacity of the pump J, the sizes of the various orifices and other elements which determine the operating functions of the mechanism.

In Figs. 1 to 16, the various parts are illustrated in their poistions of operations when the car is being driven forwardly in a direct drive through the main transmission B and the overdrive transmission A. .It will also be noted that the accelerator pedal 245 is illustrated in Fig. 3 by the solid line position as being depressed to a position within the operating range of the'throttle valve 256 whereby the pin 238 is positioned at a point intermediate the ends of the slot 231 of the sector 236. This allows the sector 235, lever 225, Bowden wire 223 and the valve M to assume positions as illustrated in Figs. 3 and 11, independently of any influence from the accelerator the sector 238, the lever 225 operates to exert a l pedal. Thus the spring 232' and detent 226 will hold the valve M forwardly or to the right as viewed in Fig. 11 whereby the valve isurged against the flange 2I0 of the cylinder 209, further movement being prevented by the stronger opposing spring 2 I2.

With the valve M thus positioned, this valve closes of! communication between the pressure passage 200 and the kick-down orifice 201, the

.valve likewise closingoif communication between vent passages I13 and I14 so that the relief chamber I66 to the right of valve L is closed off against escape of liquid therefrom. At this time the valve L occupies a position of venting the motor G inasmuch as the passage I which conducts pressure fluid to the motor is now open through the valve groove I41 to the venting orifice I51. The valve L also closes the drain passage Assuming that the car speed is below miles per hour, the pump J will deliver fluid through the passages I09, H0, III and into high pressure chamber I43 whence the oil escapes through the valve groove I60, sleeve groove I45 and thence through the orifice I55 for return to the pump intake at the foreshaft. The oil in pressure chamber I43 also passes through the small bleed passage I68 and into the relief chamber I66 where the oil is trapped, thereby preventing movement of the valve L forwardly or to the right until the chamber I66 is vented and, of course, until the pressure of the fluid in the chamber I43 is sufficient to overcome the effect of the preloaded spring I58 as well as the orifice I55.

The valve L will maintain the Fig. 11 position at all times during manipulation of the accelerator pedal between the positions 248 and 250 even though the car speed exceeds the assumed critical speed of 3Q miles per hour because such movement of the accelerator pedal does not operate the sector 236 and therefore the valve M remains in the Fig. 11 position preventing venting of the relief chamber I66. In the event that the accelerator pedal is at such time manipulated to the kick-down position 249, the valve M will be moved to the left so that groove 202 will establish communication between passage 200 and orifice 201 but obviously this will not have any effect on the valve L because this valve is already in the position established in direct drive in the mechanism A. In the event that the car speed increases so that pump J delivers pressure fluid in excess of the capacity of orifice I55, and with parts positioned as in Fig. 11, then the relief valve I20 (shown in Fig. 9) functions to relieve such excess pressure by unseating against its spring I2I.

, As the car starts up from rest, the flow of oil from the pump J increases very nearly proportionately to the car speed and the pressure which draws across orifice I51 increases as the square of the car speed.. At a certain predetermined car sped, depending on the size of the pump J, the diameter of orifice I51, the area of the valve L, the preload of spring I58 and other apparent factors, the valve L will move forwardly to the right provided the pressure is relieved in the chamber I 66. This car speed is assumed to be 30 miles per hour so that when this speed is reached, let us assume that the driver then releases the accelerator pedal to allow the same to move under the action of spring 241 to the fully released position thereof indicated at 246. When the pedal reaches the position 250, the stop 238 picks up the sector 236 and as the accelerator pedal'moves to the position 246, the is moved to the position 25I.

This movement of the sector operates to push through the Bowden wire 223 to swing the lever 22I and the plate 2" as a unit in a clockwise direction, as viewed in Fig. 11, about the pivot 220, thereby causing the valve M to more forwardly against the spring 2I2 which is relatively weaker than the spring 241 until the valve M occupies the position illustrated in Fig. 17.

At this time the plate 2I1 is carried free of the detent 226 and the valve M continues to close the upper end of pressure passage 200. However, the valve groove I99 is now moved into alignment sector 23.

' with passages I13 and I14 so that these passages establish communication between chamber I66 and the vent at I16. it being assumed that the dash control valve N has been left in the position illustrated in Fig. 11. Venting of the chamber I66 can at all times be prevented by the operator pulling the knob I so that the head I84 of valve N closes the upper end of vent passage I14 so that regardless of the position of valve M, the chamber I66 canont be vented and the valve L will not under any conditions move from the Fig. 11 position. In this manner I have provided a convenient means of maintaining the mechanism A in direct drive.

As soon as the valve M is moved from its Fig. 11 position to its Fig. 1'1 position to vent the chamber as aforesaid, the valve L will start to move to the right due to a pressure differential between its ends at chambers I43 and I66, this pressure differential being greater than the preload of spring I58 and-the first effect of this valve movement will beto partially block off the oil fiow through the sleeve ports I48. This will cause the pressure in the chamber I43 to increase additionally and thereby cause the valve L to move further and faster to the right. Movement of the valve L will be forced, after it once starts moving, until the oil flow is changed by cutting off the flow through the ports I48 and opening .the ports I49 to the pressure chamber I43 by registration of the latter ports with the annular groove I6I of the valve L.

It might be noted at this point that the area of the passages I12, I13 and I14 are preferably so much greater than the area of the bleed passage I 68 that when the chamber I66 is vented the pressure in this chamber will be dropped to a negligible value. The valve L thus moves to the right until it assumes the position illustrated in Fig. 17 which might be termed an intermediate dwell point of momentary duration during. movement of the valve from the direct drive position in Fig. 11 to the overdrive position of Fig. 18. At this point the valve has moved to close off the sleeve ports I48 to shut off the flow through the restrictive vent and orifice I55 and the annular valve groove I6I is slightly open to the sleeve ports I49 for supplying the pressure fluid from the chamber I 43 to the motor G.

As this takes place the valve momentarily hesitates at this point because of the pressure drop in the chamber I43 due to opening of the pressure chamber to the supply line leading to the motor G. At the same time the valve groove I62 is open through sleeve ports I50 to the restrictive vent through orifice I51 so that a portion of t fluid flow is vented through this orifice durin the time that the supply line to the motor G is filling and effecting engagement of the brake Fagainst the resistance of the springs 81 and 18.

I have found that the pressure moves the valve L as aforesaid and good results are obtained by roughly a third of the oil delivered at the valve groove I82 passing through the orifice I51 which, of course, leaves the bulk of the oil for delivery to the motor G for applying the brake. Thus the orifice I! functions to prevent a water hammering effect while the line is filling to the motor Gpnd I have thus provided several distinct cushionlngeflects for engaging the brake F. One of these cushions functions by reason of the orifice I'b'btaking apart of the oil which is suddenly admitted to the ports I49 while the other cushionin'g'eifect is supplied by reason of the springs 8'! and I8 being further compressed during the engagement of the brake F.

As soon as the brake discs are engaged with each other at the brake F, then at this instant the pressure in the delivery passage I rises rapidly and the valve L is thereby pulled further to the right as a result of the increased pressure resulting in an increase of the flow of the oil through the orifice I57 which further cushions the final stages of the engagement of the brake F and results in what may be termed a dash pot action of the engagement of the brake. At this time the valve L is moved to the Fig. 18 position from which it will be noted that the orifice l5? cont'inues"to restrictlvely vent the passage I25 while the ports I 48 continue to be closed by the valve L.

By preference, the length of the annular groove use is about equal to or slightly less than the longitudinal distance between the sleeve ports I43 and M9 to facilitate rapid movement of the valve L to the right to attain a more positive snap action in the valve movement. When the valve L has been moved to the Fig. 18 position, it will be noted that this movement is limited by the stop I61 and that at this time the relief passage I'lZ is closed by the valve and also that the valve groove 563 is now aligned with the vent passage no which preferably has substantially the same capacity of the system of vent passages I'I2, Il3 and IM. IE6 is now open to the drain passage H5 independently of the drain and the annular groove I99 of the valve M and the accelerator pedal may therefore be depressed while maintaining the chamber I66 vented.

The orifice I5? is appreciably smaller than the orifice I55 so that if the car speed was sufllcient to overcome the flow through the orifice I55 and thereby move the valve L to the right, then it will be more than sufficient to maintain the valve L to the right in the Fig. 18 position and thereby prevent a hunting tendency of the valve.

Furthermore, the orifice I5? controls the speed at drop in the pressure of chamber I43 whereupon the spring, I58 comes into action to restore the valve L from the Fig. 18 position to the position illustrated in Fig. 11, thereby venting the motor G and again opening the.chamber I43 to the re-' In this manner the mechanism A is automatically operated for ast'ep-down in the speed ratio drive in response to some predetermined point preferably lower than that at which the step-up of the speed ratio in mechanism A takes place.

Let itnow be assumed that the valve L is in the overdrive position illustrated in Fig. 18 and that the accelerator pedal 245 is at some point intermediate the positions 248 and 246 with the car travelling at, a relatively high speed such as 45 miles per hour for example. Under such conditions the driver may at any time effect movement of the valve L back to the Fig. 11 position for restoring the direct drive from the mechanism by depressing the accelerator pedal to the kick-down position 249 thereby maintaintaining the throttle valve 256 in its wide open position and move the sector236 by going to the position thereof at 252, the lost motion deby the valve M while the annular groove 202 In this manner the chamber the mechanism A from the overdrive to the d rect 7 drive. This will take place preferably at a lower car speed than that at which the overdrive will engage and is preferably in the neighborhood of 16 to 20 miles per hour, the latter figure earlier having been referred to for purposes of illustration.

I preferably employ a preloaded type of spring I58 as this has important commercial aspects in the overdrive to the direct drive.

of the valve M is moved to establish communication bet-Ween the branch pressure passage 2% and the restrictive vent through the orifice 257. This orifice has sufiicient capacity to vent the pressure chamber I43 to allow the spring I58 to move the valve L to the Fig. 11 position although, as aforesaid, the orifice. 20? will preferably not accommodate such venting of the chamber M3 when the car speed is in excessof a predetermined value such as 60 miles per hour for example. In the illustrated car speed of 45 miles per hour and with the kick-down of the valve M to the Fig. 19 position, the valve L will be restored to the Fig. 11 position, thereby effecting a step-down in the mechanism A from When the kick-down has thus been operated by the pin 233 moving the sector 235 to the position 252, my arrangement is such, by preference, that the valves L and M will be left in the Fig. 19 position until the accelerator pedal is substantially fully released. When the valve M is in the Fig. 19 position, it will be noted that the detent 226 acts to prevent this valve from moving to the right when the accelerator pedal is released from the position 249 so that the valve will stay in the Fig. 19 position until the-accelerator pedal approaches the position 250 at which time the pin 238 will engage the right hand end of the slot 231 and cause the sector 235 to move the lever 22I clockwise as viewed in Fig. 19, thereby releasing the plate 2|! from the detent 226. Then as the accelerator pedal is further released from the position 250 to the position 245, the valve M is forced to move as aforesaid into the Fig. 1'7 position for venting the chamber I56 and thereby allowing the valve L to move to the right to again restore the overdrive in mechanism A.

- the kinetic efiects of the oil flow. The viscosity factor varies greatly with the temperature changes when the usual fluids employed in transmission control are used. The kinetic effects on the other hand vary only as the densityof the liquid is changed and this is such a small factor as to be negligible within the limits of temperature variation ordinarily dealt with and experienced with motor vehicle operation.

A sharp edge orifice has a minimum of length and surface over which the oil is in shear and therefore presents a minimum of variation due to the viscosity effect and thus this type of orifice presents a minimum total variation allowing a wide selection of fluids without corresponding variation in the operation of the device. The sharp edge orifice therefore carries the desirable effects substantially to the point where the mechanism controlled by the valving device K functions Just the same in summer as in winter and for all practical purposes the same regardless of the density of the liquid employed, thereby making my control mechanism especially suited for commercial use. By substituting other sized orifices for those illustrated, I can, of course, obtain a wide variation in the functions of the mechanism as will be readily understood. The desired effects can be approached by the use of a thin plate orifice although I prefer to additionally provide the sharp edge of orifice opening in order to still further render the apparatus free from temperature variations and changing density in the oil medium.

Referring to the modified arrangement illustrated in Figs. and 21, I have shown my valving device K modified by the provision of a continuously open vent for the relief chamber I68, thereby dispensing with the aforesaid annular groove I99 in the kick-down valve M and also eliminating the bleed passage I88 and the provision of the dash control N. This arrangement also is preferably accompanied by the elimination of the free center function of the kick-down valve while the accelerator pedal is manipulated throughout the throttle opening range because now the accelerator pedal does not.control the venting of the chamber I66. Inasmuch as most of the parts are identical in general function and structure with the corresponding parts aforesaid, I have provided the same reference characters to Figs. 20 and 21 for such parts and will only describe such differences as may occur over the Fig. 11 type of mechanism.

In Figs. 20 and 21, the main valve L is free to move to the right at any time when the fluid pressure in the chamber 3 rises suificiently to overcome the resistance of the preloaded spring I88 provided of course that the kick-down valve M is in the kick-down position which is illustrated in Fig. 20. This valve movement may take place by reason of the chamber I66 being vented at. all times through the sleeve and easing passages 210 and 2', respectively, the latter opening to the bore 212 for slidably receiving the valve M. This bore is continuously open to the vent passage 213 which leads to the reservoir III! in the same manner as previously referred to in connection with the vent 'passages I" and I for example. The valve M is now connected through a link 2' with a lever 21! which takes the place of the aforesaid plate 2H and is likewise fixed through the pivot shaft 218 with the upper end of a lever 21'! which takes the place of the aforesaid lever 22! and is likewise adapted for actuation by connection with the Bowden wire mechanism 228.

The accelerator pedal 218 is illustrated in the kick-down position having been moved from the wide open throttle position 218 for causing the pin 288 to pick up the sector 281-. Assuming that the parts are positioned as illustrated in Figs. 20 and 21, it will therefore be apparent that the vehicle driver has depressed the accelerator pedal to the position 219' for pulling through the Bowden wire 223 to move the kick-down valve M to the left, thereby venting the pressure chamber I48 and allowing the valve L' to move from the overdrive position tothe direct drive position in approximately the same manner as described, it being noted that by preference the restrictive vent of the chamber I" is obtained by the aforesaid orifice 201.

When the driver releases the accelerator pedal from the kick-down position, the pin 280 will move in the sector slot 282 allowing the sector 28| and valve M to stay in the illustrated positions until, Just before the accelerator pedal is fully released, the pin 28!) engages the right hand end of slot 282 so as to pick up the sector 28l and pull through the Bowden wire 228 and thereby move the valve M' to the right for closing the pressure branch passage 288 as before described,

When releasing the accelerator pedal from the kick-down position, the valve L will then immediately move to the right, provided of course .that the car speed is such to cause delivery of oil in' chamber I48 at a pressure sufficient to overcome the effect of spring I58 and the restrictive vent through the orifice at I55, and thereby cause the mechanism A to change from the direct drive to the overdrive.

Referring to the embodiment of my invention illustrated in Figs. 22 to 24, I have arranged my pressure fiuid control device for effecting automatic engagement and disengagement of a clutch disposed at some point in the line of power transmission of the engine drive to the motor vehicle. In the particular embodiment illustrated, I have provided a drive to the pump taken from a part which operates at a speed proportionate with the engine speed so that the clutch will function in relationship with the engine speed rather than with the car speed as in the earlier embodiment. One desirable application of such an arrangement is in connection with a drive embodying a fluid coupling in connection with which difficulty has been experienced by reason of the inherent drag in the coupling making it difficult to release the drive through the coupling when the engine is idling or running at relatively low speed.

In the present embodiment of my invention, I have therefore provided a novel arrangement of interposing a pressure fluid operated clutch in the line of drive between an engine driven fluid coupling and a power delivery device preferably in the form of any suitable type of transmission together with my fiuid control mechanism so arranged that when the engine speed decreasesv to a predetermined value, say in the neighborhood of 500 to 600 'R. P. M., the automatic valve will operate to release the clutch in substantially the same manner that the brake F was released by the automatic valve in the earlier embodiment of my. invention. Also, when the engine speed increases above the aforesaid predetermined value, then the automatic valve will operate to bring about engagement of the clutch, the arrangement being such that the drive to the transmission is automatically intercoupling N, this impeller having the well-known.

vanes 29I for guiding fluid contained in the coupling outwardly by centrifugal force toward a runner member 292 having similar vanes 293.

The runner member 292 is fixed to the driven shaft 294 which drives the friction plates 295 of the clutch O. This clutch has a driven member 295 carried as a part of the shaft 291 which preferably is the input shaft to any suitable type of transmission generally designated at P from whence the drive passes through the output shaft 298 for driving the ground wheels of the motor vehicle.

The clutch driven member 296 drivingly carries the driven friction members 299 and 300, the latter comprising a pressure plate movable rearwardly to pack the driving and driven clutch plates for engaging the clutch. Clutch engagement is efiected by rearward movement of an annular piston 30I slidably arranged in the annular cylinder 302 having a fluid inlet 303 leading to the valving means K which is substantially identical with that illustrated in Fig. 20. In other words, the pressure fluid outlet I25 of Fig. 20 now leads to the cylinder 302 of Fig. 22 while the pressure fluid delivered to the valving device K is now admitted through a pipe 304 from an suitable type of pump 305 arranged in the reservoir or sump 308 of the casing structure 807.

The pump 305 is driven by a gear 300' meshing with driving gear 301 carried by the rear cover member 308 which is formed as a part of or is secured to the impeller 290 and therefore drives with the engine C.

A portion of the valving means K is illustrated in Fig. 23 and differs only from that-illustrated in Fig. 20 in the following respects. Instead of a restrictive vent cooperating with the annular groove 202 of the valve M, I now preferably pro vide a freely open vent for the passage .200 through the passages 309 and 3I0 so that the main valve L may be returned to the position illustrated in Fig. 20 independently of car and engine speed whenever the valve M is moved to the position shown in Fig. 23. Also in this arrangement, the lever 21! of Fig. 20 is now replaced by a clutch pedal 3 normally returned by a suitable spring diagrammatically illustrated at 3I2 which tends to move the valve M to the right for closing off the passage 200 and maintaining the main valve L in-its position against the stop I61 whenever the pressure of the fluid in the chamber I43 is suflicient to move the valve against the action of the preloaded spring I58.

In the operation of the embodiment illustrated in Figs. 22 to 24, let us assume that the vehicle is at rest. If desired, the clutch pedal 3| I may be depressed in starting the engine or of course the engine may be set with the transmission P set for neutral so that the car will not start on starting the engine. When the engine is started with the a pedal 9| I, the transmission P may be manipulated to any desired drive from shaft 291 to shaft 298 and the engine accelerated in the usual manner as the clutch pedal 3 is released. As thespeed of the engine increases above its idling point, the main valve L will move to the right and will cause the fluid pressure to be delivered from the supply pipe 304 to the delivery pipe 303 for engaging the clutch O and establishing a drive from the engine to the output shaft 298. During this time the fluid coupling N operates in the customary. manner to decrease the slip therethrough as the speed of the engine increases.

When it is desired to manipulate the transmission P for changing the gear ratios therein, the pedal 3 may be depressed to vent the pressure chamber I43 through the passages 399 and 3I0, thereby causing the clutch O to disengage for the purpose of shifting gears in the transmission P.

When the vehicle is brought to a temporary.

stop as when the car approaches a red trafilc signal for example, the transmission may be left in gear if desired and asthe brakes are applied to the vehicle and the engine speed is brought down approximately to its idling condition, the pressure of the fluid delivered by the pump 305 will have diminished sufficiently to enable the spring I58 to return the valve L to the Fig. 20 position, thereby venting the cylinder 302 for causing the clutch O to disengage. In this manner, the en= gine C is released from the output shaft 295 and the valving device K acts as an automatic control on the drive in response to idling of the engine. When the tramc light shows green, then the driver need only to accelerate the engine C causin a corresponding increase in pressure fluid delivered from the pump 305 to the pressure chamber I43 thereby causing the valve L to move to the right and admit the pressure fluid to the cylinder 302 for engaging the clutch 0 preferably through the cushioning means aiforded by the restrictive vent at the orifice I5! which functions in a manner generally similar to that in connection with the Fig. 11 device.

Various other applications of my improved valving device will be readily apparent from the foregoing illustrative embodiments and also various changes in the details of construction and mode of operation may be apparent from my description and it is not my intention to limit my invention apart from the scope anorded by the appended claims within the broader aspects of my invention.

I claim:

1. In a power transmission control mechanism of the character described having a pressure fluid operated device comprising relatively rotatable frictionally engageable elements for controlhng drive transmission between driving and driven shafts of a motor vehicle, a source of fluid supply, a pump for delivering the fluid under pressure from said supply, means for driving said pump at a speed proportionate to one of said shafts for delivering the fluid under pressure varying with the speed of this shaft, a valve adapted for movement from a first position of venting said device thereby to accommodate relative disengagement of said elements, to a second position for establishingv communication between the pressure fluid delivered by the pump and said 

